Test output will be located in test.rb file.

will give example output for:

1. Block and Yield,
2. Proc,
3. Lambda,
4. there is also Methods.

why? because decisions must be made. helpful links:
http://awaxman11.github.io/blog/2013/08/05/what-is-the-difference-between-a-block/
http://www.eriktrautman.com/posts/ruby-explained-blocks-procs-and-lambdas-aka-closures

output could be improved to give comments on each thing.
block and yeild
1!2!3!

block without yeild
246

block using do
2
4
6

Proc using &
2
4
6

Proc using .call
Hello World

Lambda using &
2
4
6

Lambda using .call
Hello World